Scene-shifting device for projection apparatus.



'W. L..PATTERSON.

SCENE SHIFTING DEVICE FOR PROJECTION APPARATUS.

APPLICATION FILED AUG. I, 1913.

Patented May 22, 1917.

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W. L. PATTERSON.

SCENE SHIFTING DEViCE FOR PROJECTION APPARATUS.

APPLICATION man AUG-1,1913.

1,226,806. Patented May 22,1917.

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WILLIAM PATTERSON, or ROCHESTER, NEW YORK, AssIeNoR To RAUscH & LOMBOPTICAL COMPANY, or RocnEs'rER, NEW YORK, A CORPORATION OF NEW YORK.

SGENE-SI-IIFTIN G DEVICE FOR PROJECTION APPARATUS.

Specification of Letters Patent.

Application filed August 1, 1913. Serial No. 782,400.

To aZZ whom it may concern:

Be it known that I, WILLIAM L. PATTER- SON, of Rochester, in the countyof Monroe, in the State of New York, have invented certain new anduseful Improvements in Scene-Shifting Devices for Projection Apparatus;andI do hereby declare the following to be afull, clear, and exactdescription of the same, reference being had to the accompanyingdrawings, forming a part of this specification, and to thereferencenumerals marked thereon.

My present invention relates to the projection apparatus and hasfor itsobject to provide means for shifting or changing the scene, whereby oneprojected image may be caused to displace another on the screen in sucha manner that no apparent movement of the two images occurs, thesubstitution of one image for the other producing the apparent effect ofone picture being applied by being wipedacross the screen as the edgeofthe other picture is taken up or disap pears. In other words themeeting edges of the advancing and receding views respectively move ontoand off from the screen within a zone marked by the meeting rays of twoparallel systems of lenses, said zone v or point traveling across thescreen in one direction or another as the angle of the light raysthrough the lenses varies by reason of the shifting of either the lensesrelative to the light source or the moving of the light source out ofaxial alinement with one lens system into alinement with the other. Tothese and other ends my invention consists in certain improvements andcombinations of parts all as will be hereinafter more fully describedthe novel features being pointed out in claims at the end of thisspecification.

In the drawings:

Figure l is a top plan view of an apparatus constructed in accordancew1th my invention illustrating one embodiment thereof;

Figs. 2 and 3 are front and side elevations respectively, and

Figs. 4 and 5 are diagrammatic illustrations showing the device indifferent positions of adjustment, and the path of the light rays.

Similar reference numerals in the several figures indicate similarparts.

My invention comprehends a device for use in connection with pictureprojection apparatus which is adapted to be employed for changing theimages of pictures projected on the focusing screen, in a mannerpleasing to the observers eye and it differs from the so-calleddissolving view mechanism in that instead of the image of the firstpicture gradually dissolving, or fading away, asthe intensity of thesecond picture increases, it permits the simultaneous showing of imagesof two pictures with equal clearness, or intensity of illumination. Inthe operation of the device the image of the second picture appears toadvance across the screen and in effect creates the impression as if itwere sliding over and being superposed upon the image of the firstpicture. Optically considered "the advancing edge of the image of thesecond picture is laid on the screen by light rays admitted through onelens system as the adjacent edge of the image of the first picture is removed by the cutting oif of the light rays passing through the otherlens system; the line of demarcation between the two images being ratherwell defined and so 'much of the images of the two pictures as appearupon the screen are correspondingly illuminated.

The apparatus generally described for accomplishing my present inventioncomprises a plurality of projecting lens systems arranged injuxtaposition and composing one element, together with a source of lightwhich forms the second element of the in vention. Said elements are sodisposed that one iscapable of movement laterally relatively to theother, whereby the pencil of light rays which may fully illuminate onelens system may be caused to enter an adjacent lens system and finallyfully illuminate. it, the transition of the pencil of light rays fromone lens system to the other serving to effect the apparent advance andreceding of the meeting edges of the two projected images.

In carrying out my invention I employ a plurality of projecting lenssystems, two of such being shown in the present disclosure PatentedMay'22, 1917.

produced in the operation indicated by A and B. These lens systems arearranged side by side and supported in any convenient mounting such asthe box C which may also constitute a holder for the transparencies, orobjects of which images are to be projected. In the presentillustrations the object holders are indicated by a and 7) which areadapted to accommodate the usual lantern slides. If desired the lens'systems may also comprise the collective lenses A and B arrangedadjacent to and in rear of the object holders and also carried on themounting C. The separate lens systems with their respective objectholders and condensers are secured in their relative positions andtogether constitute one element of the apparatus. If this element is tobe the movable part of the apparatus then the mounting C is supportedfor adjustment in the plane of the axes of the lens systems, i. e. ifthe lenses are arranged in a horizontal plane they will be capable ofmovement in either direction horizontally, or if said lenses aredisposed one above the other then the mounting in which they are carriedwill be supported for vertical movement. In the device just describedthis adjustment is pro vided by forming on the bottom of box C a guide 1carried in ways 2, on a standard 3 which is preferably adjustablysupported on the bed 4: of the projection apparatus.

The source of illumination indicated by D, Figs 4 and 5, constitutes thesecond element of the apparatus and in practice is located in such aposition that the pencil of light rays emanating therefrom willilluminate one or the other of the systems of projection lenses whenthese are in alinement with it, and during their movement transverselywill serve to illuminate parts of both lens systems. The light rays arepreferably collimated by a condenser E which cooperates at all timeswith the collective lenses A and B.

In Figs. 4: and 5 I have shown diagrammatically the arrangement of thelens systems, the source of light and the direction of the light rayswhich fall upon the focusing screen F. The two lens systems A. and. Baresubstantially alike so that the same field is covered by the raysprojected by each of them and the sizes of the images projected by thelenses are equal; although this is not necessary and is a condition thatis desired only because of the more pleasing effect of changing from onescene to another. In the transition which occurs upon the relativemovement, or shifting, of one element of the apparatus, with respect tothe other, the pencil of light rays enters both of said lens systemswith the consequent result that the converging rays of light, asindicated by the lines a and b cross each other ,and produce on thescreen a zone 7, which marks the meeting edges of the images of the twopictures. It is in this zone that the new picture seems to be createdand the old or previous picture seems to be dissolved. In order toreduce the width of this zone to a narrow line and to eliminate as faras possible the haziness in the images of the tWo objects at each sideof this line, caused by chromatic aberration, I provide a diaphragm G,interposed'between the condenser E and the collective lenses A and B,having an aperture the edges of which cut the rays of light entering theprojecting lens systems so that the converging rays a and b will becaused to meet at the surface of the screen F, irrespective of theirrelative angular relations.

In the operation of the scene shifter let it be assumed that the lensesoccupy the position shown in Fig. 4: in which the image of thetransparency a is projected onto the screen F by the lens system A. Theoperator desiring to change the scene inserts the slide or transparencyb in its holder and shifts the lens mounting C in the directionindicated by the arrow. During this movement the lenses A are carriedout of the path of light as the lenses B are brought into it andwhen thelenses B have advanced sufliciently to receive part of the light raysthe new picture, or image, begins to appear at one edge of theilluminated area of the screen. The new picture continues to grow insize and the previous picture gradually diminishes in area as the twosets of lenses move across the path of the light rays until the image ofthe object Z) occupies the entire field of the screen F.

In order to conveniently adapt the appa ratus for use under variousconditions I make the diaphragm G adjustable, using apertured plates 9and g which are adj ustably mounted in a support or holder g attached tothe bed I. These plates are arranged so that their edges overlap andthey may be adjustably secured to the holder by means of bolts whichpermit them to be moved relatively to determine the size of the apertureand also allow them to be moved together and positioned centrally withrespect to the source of illumination and the condenser E.

I claim as my invention:

1. In a scene shifting device for projection apparatus, the combinationwith a source of parallel light ray illumination, of two separatesystems of projection lenses arranged together as a unit, said unit andsource of illumination being movable relatively to each other toilluminate one or the other of the separate lens systems, said partsbeing disposed to illuminate areas of both projection systems duringsaid movement.

2. A scene shifter for projection apparatus comprising two adjacentsystems of proj ecting lensesmfounted together, and a source ofillumination providing parallel light rays, said lenses and source ofillumination being bodily movable relatively transversely to cause the"full illumination of one or the other of said lens systems and thepartial illumination of both systems during said movement. 1

3. In a projecting apparatus, the combination with a source ofillumination and two systems of projection lenses arranged adjacent onebesidethe other and capable of being reciprocated laterally of thepencil of rays to alternately position one or the other of said systemsin alinement with the source of illumination, said light source beingcapable of illuminating areas of both lens systems during, theirshifting movement.

4:. In a projection apparatus, the combination with a source ofillumination, of two systems of projection lenses arranged side by sideand together movable transversely of and in the column of light rays,the diameter of the latter being such that during said movement parts ofboth lens systems are illuminated.

5. In a projection apparatus, the combination with two systems of lensesarranged side by side, of a source of parallel light rays,said twolenses and said source of light being movable relatively one to theother in a direction transversely to the axes of the lens systems, thelatter being so arranged that during their movement complementary partsof each will be illuminated.

6. In a projection apparatus, the combination with two systems of lensesmounted in juxtaposition to each other, of a column of light, said twolens systems and said light source being movable relatively one to theother transversely in the plane of the axes of the two lens systems anda diaphragm for defining the limits of the field illuminated by thelight column when comple mentary parts of the two systems areilluminated.

7. In a projection apparatus, the combi nation with a source ofillumination providing parallel light rays comprising one element, oftwo projection lens systems mounted in juxtaposition, comprising asecond element, one of said elements being shiftable laterally of theaxis of the other and a diaphragm arranged between the light source andthe lens systems and limiting the area of illumination during the timeparts of the two lens systems are illuminated.

8, The combination with two systems of projection lenses connectedtogether and movable in the plane common to their axes, of a source ofillumination and a diaphragm arranged to cut the column of light raysand control the width of the zone between the meetingedges of two imagesprojected on a screen when said two lens systems are in a position wherethe column of light rays passes into both lens systems.

9. The combination with two parallel systhe time when the latter aremoved across the path of said rays.

1Q. In a projection apparatus, the combination with a source ofillumination and a condenser for paralleling the light rays, comprisingone element, of a plurality of projection lens systems each embodying anobject holder and a collective lens all constituting a second element,one of said elements being movable relatively to the other and a andlimiting the area of the light column during the time parts of both lenssystems are being illuminated.

11. In a scene shifter for projection apparatus, the combination with aplurality of separate systems of projection lenses mounted side by side,each system comprising a condenser and an object holder in front of eachcondenser, of a source of parallel light ray illumination, said lenssystems and said source of illumination being arranged for relativelateral movement and disposed to cause the light rays to enter said lenssystems successively and illuminate parts of the adjacent systems duringsuch movement.

12. In a scene shifter, the combination with a plurality of separatesystems of projection lenses, an object holder in rear of each systemand condensers in rear of the holders, said lens systems, holders andcondensers comprising one element of the structure, of a source ofillumination for said lens systems, and a condenser between it and thelens systems, said source of illumination and its condenser comprisingthe second element of the structure, said first and second elementsbeing capable of relative movement to successively direct the column oflight rays into the different systems of projection lenses and duringsuch movement to direct portions of such rays into two adjacent systemsof lenses.

13. In a scene shifter for. projection apparatus, the combination withan illuminating system, and a projection system comprlsing two adjacentand substantially parallel projection devices, of means for mountingsaid systems to permit shifting thereof transversely of the opticalaxis, said systems being so disposed that complementary areasilluminated during the shifting movement.

85 diaphragm interposed between the elements 1 L. In a scene shifter forprojection apparatus, the combination With an illuminating system, aprojection system comprising tWo adjacent and substantially parallelprojection devices, and means for supporting picture devices to beilluminated in the optical axis of each of the projection devices, ofmeans for mounting said systems to permit shifting thereof transverselyof the op- 10 tical axis, said systems being so disposed thatcomplementary areas of the pictures formed by the two projection devicesare illuminated during the shifting movement and are substantially equalto the entire area of a picture formed by one of the projection devices.

WILLIAM L. PATTERSON.

Witnesses DANIEL M. SMITH, WILLIAM G. WOODWORTH.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, .D. G.

